There are two sets of rules, both of which would result in a $500 credit.
1. Qualifying child
Your brother can be your "qualifying child" dependent if he is,
- younger than you
- lives in your home more than half the year
- does not provide more than half his own support
- is "disabled."
For dependent purposes, disabled means "unable to perform substantial gainful work, due to a condition that is permanent, or will last at least one year, or will lead to death." The key is "performing substantial gainful work." If your brother can work a regular job, even minimum wage, with minimal special accommodations, that is an indication he can perform gainful work. If he can only work in a sheltered workshop, that is not gainful work. The gainful work test may be different than the test applied by SSI or the VA or other agencies, and he does not have to be certified by another agency as disabled to be a dependent, although it may help. (Conversely, many people who are "disabled" in the physical sense, can still perform gainful work and are not disabled for tax purposes.)
2. Or, he can be a dependent under the "qualifying relative rules." The only factors that relate to your situation is that you must provide more than half his financial support, and he can't have more than $4200 of taxable income. He does not have to live with you, doesn't have to be disabled, and can be any age. For support, you consider who provides support (you, SSI, other family members, etc.) and see if you pay more than half the total. Disability income is not taxable for the taxable income test but does count as support for the support test.
